Diaphragm for acoustic apparatus.



W. BURSTYN. DIAPHRAGM FOR ACOUSTIC APPARATUS.

APPLICATION TILED FEBJQ, 1909.

. Patented Apr. 12, 1910.

warn'rnnn .BUBS'TYN,

DIAPHRAGM FOR A OF BERLIN, GERMANY.

COUSTIC APPARATUS.

To all whom it may concern:

Be itknown that I, \VALTHER BURsTYN,

' aforesaid contradiction of these conditions,

U except in its e ge,

' oscillation loop has one is prevented from passing that size of diaphragms as it is now customary in telephones, microphones, phonographs etc. If greater acoustic energies are to be converted, one is forced to use simultaneously a number of single apparatusof the customary size, for instance to connect in parallel. i

My'invention has for object to obviate this ditticulty by putting the diaphragm into such a shape that it possesses, in spite of its small thickness, a high periodicity of natural vibration.

Inthe accompanying drawing: Figure 1 is a cross section through part of a tele-- phone, showing my improved diaphragm; Fig. 2 a similar section, showing a modification; Fi 3 a plan of afurther modification, an Fig. 4 across section through a phonograph-diaphragm and adjoining parts. Accordingto my invention a diphragm. a, is employed which is supported in one or several .s ots. In the most simple construction, a disk sha ed diaphragm a is lfastened, in its center so that the the form of a circle. Fig; 1 shows a sectional view of a particularly advantageous arrangement in which the diaphragm a has the form of a ring. As will be seen from the drawing,the iron case at preferably forms a ring ofa U-shaped section the opening of which is opposite to the center-line of the annular diaphragm a, and in the cavity of which is located the ringshaped magnetizing coil e. The telephone according to Fig. 1 does not contain a steel- Specification of Letters Patent.

several microphones Patented Apr. 12, 1910.

Application filed February 19, 1909. Serial No. 478.551.

In this construction, either an additional magnetizing direct current is sent through the coil, or case (Z is made of steel and permanently magnetized.

It will be understood that, instead of one ring a, there maybe arranged several concentric rings a a as represented in Fig. 2. In a microphone having such a diaphragm, the cloth bags f containing the carbon powder, or their substitute means, are also suitably arranged in the shape of a ring, the spots of contact touching the oscillation loops of the diaphragm. If the microphone is intended to possess a high resistance, the carbon powder ring fis suitably cut up, as shown in Fig. 3, at g g, the ends 9 g" serving for introducing the current.

In a diaphragm for phonographs, the means for transmitting the movement consist in little staffs or needles h, as represented in Fig. 4 showing a diaphragm a for phonographs, the diaphragm being supported in its center by appropriate arms 2'. The said staffs k suitably form the envelop of a cone, the base-circle of which is formed by' those points A: of the diaphragm a to which the stafi's h are secured, the said points A: lying simultaneously in the centerline of the diaphragm a. The apex of the cone bears the recording stylus 'm.

It will be understood that the diaphragm may be divided .intb sections or strips of other shape as above described, without differing from the principle of my invention, This principle is not only appropriable to plane diaphragms but also to cylindrical or spherical ones.

What I claim, and desire to secure by Letters Patent of the United States, is

1. In a device of the character described, an annular case, a diaphragm clamped thereto at its circumference, and rigid means for supporting the diaphragm at-its center.

2. In a device of the character described, an annular case, a diaphragm clamped thereto at its circumference, rigid means for supportin the diaphragm at its center, and vibration receivin means located intermediate the circum erence and center of the diaphragm.

3. In a device ofthe character described, an annular case, a diaphragm clamped theremagnet. v

to at its circumference, rigid means for supdiaphragm intermediate its circumference porting the diaphragm at its center, and a and center.

ayer of carbon powder located below the In witness whereof I have hereunto set diaphragm and intermediate the circum I my hand this sixth day of February 1909,

5 ference and center thereof. b d in the presence of two subscribing witnesses. 15

4. In a device of the character descri e r an annular case, a diaphragm clamped there WALTHER BURSIYN' to at its clrcumference, rigid means for sup- Witnesses: porting the diaphragm at its center, and a HENRY HASPER,

0 concentric ring on the case that supports the WOLDEMAR HAUPT. 

